An inquest into the disappearance of a NSW teenage girl almost 17 years ago has found she was likely murdered by one or more people, breathing new life into one of the state's most intriguing cold cases.

Jessica Small was abducted from Bathurst, west of Sydney, alongside Vanessa Conlan in 1997 and while Vanessa managed to escape, her best friend has not been seen since.

A coroner found police failed to adequately investigate the abduction at the time but this month's inquest named two people who were of interest almost two decades later.

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Jessica Small was abducted from Bathurst, west of Sydney, alongside Vanessa Conlan in 1997 and while Vanessa managed to escape, her best friend has not been seen since

Eight months after Jessica vanished, two forestry workers found a pair of girl's underwear, a bottle of bleach and a blanket covered in blood in bushland 75km east of Bathurst

The two then 15-year-old girls were leaving an amusement arcade in Bathurst at midnight on October 25, 1997 when a man in a white car approached them and offered them a lift home.

The girls, who had been described as a troublesome pair, got in the car and the man attacked them a short time later on a deserted rural road.

Vanessa managed to escape and ran to a nearby home for help but police did not initially believe her version of events and failed to properly interview witnesses or potential witnesses that could have uncovered crucial evidence.

Detective Sergeant Peter Smith from the NSW Homicide Squad took on the cold case in 2007.

'It doesn't make sense that this girl would run screaming and obviously terrified to a person's house in the middle of the night, and then to have people not believe her, it just doesn't make sense,' Mr Smith told Channel Nine's 60 Minutes in an interview on Sunday night.

'Given especially now, 16, 17 years has passed and she's maintained the same story and it's corroborated over and over and over again. It's just so obvious that she is just telling the truth.'

Detective Sergeant Peter Smith from the NSW Homicide Squad took on the cold case in 2007 after a coroner found police failed to adequately investigate the abduction at the time

Mr Smith said one of the key witnesses who had initially been ignored by local detectives had a strange conversation with a man who matched the description Vanessa gave of her attacker.

'(He said) an adult male had been in the amusement centre asking about Jessica and actually pointed her out and said, “She looks like she's up for a good time, who is that?” And then, during that conversation, he made mention that he was an employee of the Oberon Timber Mill,' he told the program.

'I just couldn't believe that no-one had asked him about that before. It's just so important.'

The newly formed investigation team interviewed 400 men throughout 2011 who had worked at the Oberon Timber Mill at the time Jessica went missing.

They narrowed the list down to two and they were listed as persons of interest in the inquest into Jessica's disappearance.

'(One) had access to a white VK Holden Commodore with holes in the passenger foot well. The car that the girls get into on the night, Vanessa sits in the front seat. And as it's driving along, Vanessa notices there's holes in the front passenger foot well,' he said.

'That's pretty explicit. It matches acutely Vanessa's description.'

Vanessa, now 30, managed to escape and ran to a nearby home for help but police did not initially believe her version of events and failed to properly interview witnesses or potential witnesses that could have uncovered crucial evidence

The coroner, Sharon Freund, found there was no direct evidence linking the two persons of interest to the girl's abduction but said there was no evidence to eliminate them either.

Eight months after Jessica vanished, two forestry workers found a pair of girl's underwear, a bottle of bleach and a blanket covered in blood in bushland 75km east of Bathurst.

Police did not interview the person who found the items and the potential evidence wasn't DNA tested. It was later destroyed by local police.

Jessica's mother, Ricki Small, wasn't told and said she still feels let down by the police.

'I would've been in the forest scratching the dirt, looking for her, physically,' Ms Small told 60 Minutes.

'I'm hurt and I'm angry. The treatment by… local detective who were on the case was just wrong. It was abominable.'

Jessica's mother, Ricki Small, said she still feels hurt and angry by the lack of police investigation at the time her daughter went missing

The coroner has recommended that a reward of at least $500,000 be offered for information that leads to an arrest in Jessica's long-running case.

'We haven't found her. 17 years and we haven't found her,' Ms Small said.

'All I can say honestly is that I hope things were over for her quickly, if I may say it like that.

'My head's entertained the ideas of her being locked up for days, or held for days or tortured or… I hate to go there.